Catalytic epoxidation with molecular oxygen

ABSTRACT

Direct epoxidation of olefins is carried out in the liquid phase with molecular oxygen in the presence of transition metal complexes of fluorinated diketones. The additional presence of carboxylic acid ligands and free acid or its anhydrides enhances the rate of reaction and selectivity to epoxides. The olefin oxide products of the present invention are useful for formulation into polymers, and serve as starting materials for many items of commercial importance such as antifreeze compositions and the like.

United States Patent [191 [11] 3343 691 Bouloonlis 0ct. 22, W74

[5 CATALYTIC ETOXTDATTON WITH 1.209.321 10/1970 Great Britain 260/3485 vMOLECULAR OXYGEN [75] Inventor: Constantine J. Bouboulis, Union, PrimaryExaminer Norma S. Milestone [73] Assignee: lEsso Research andEngineering Company, Linden, NJ. [57] ABSTRACT [22] Filed; D c. 1, 1972Direct epoxidation of olefins is carried out in the liquid phase withmolecular oxygen in the presence of [21] Appl' 311L285 transition metalcomplexes of fluorinated diketones. The additional presence ofcarboxylic acid ligands and [52] US. Cl. 260/3485 V, 252/431 C, 260/414,free acid or its anhydrides enhances the rate of reac- 260/439 R tionand selectivity to epoxides. The olefin oxide prod- [51] lm. Cl C07d1/08 ucts 0f the present in nti ar us ful f r formula [58] Field ofSearch 260/3485 V tion into p y a serve s sta ting mat rials for manyitems of commercial importance such as anti- [56] Ref re Cit d freezecompositions and the like.

11 Claims, N0 Drawings CATALYTIC EPOXIDATION WITH MOLECULAR OXYGENBACKGROUND OF THE INVENTION 1. Field of the Invention This invention isdirected to a new and improved process for the preparation of olefinoxides. It is further directed to the preparation of in situ transitionmetal complexes of fluorinated diketones, which are found to enhance thereactivity and selectivity in the preparation of olefin oxides orepoxides. More particularly the invention relates to a process for thedirect epoxidation of olefins with molecular oxygen in the presence oftransition metal complexes of fluorinated diketones; said complexesadditionally containing carboxylic acid ligands, particularly thehindered acid varieties.

2. Description of the Prior Art Olefin oxides are extremely usefularticles of commerce. They are used as starting materials for thepreparation of antifreeze compositions, humectants, pharmaceuticalpreparations, cosmetic formulations, as monomers for the preparation ofpolymers and the like. Currently, epoxides, such as ethylene oxide andpropylene oxide are prepared respectively by the vapor phase catalyticmethod and by the classic two-step chlorohydrin route. The vapor phaseprocess is confined to the preparation of ethylene oxide, as higherolefins cannot be converted via said vapor phase process to thecorresponding higher oxides, economically.

The chlorohydrin route is an indirect method which uses hyporchlorousacid as the oxygen carrier. The hyporchlorous acid adds to the olefinicdouble bond to form the chlorohydrin, which is dehydrohalogenated withcalcium oxide to give the epoxide and calcium chloride. The disadvantageof this type process is that more than two pounds of calcium chlorideare formed per pound of propylene oxide product. The process iseconomically attractive, only when the producer is basic in chlorine andis using depreciated plant equip ment.

Another classic method is the epoxidation of olefins with peracetic acidwhich is produced by air oxidation of acetaldehyde. The process is ahazardous one, due to the explosive nature of peracetic acid, and itrequires that the equipment be of special steel in order to withstandthe corrosive action of the acetic and formic acid by-products. Theoxygen carrier is the peracetic acid and it is almost mandatory for theproducer to be in the acetic acid business, since the process results inthe production of large amounts of by-product acetic acid. Epoxides arealso produced commercially by oxidizing olefins with hydroperoxides inthe presence of molybdenum catalysts.

In US. Pat. No. 3,351,635 such a method is claimed wherein thehydroperoxide reactants preferred are materials such as cumenehydroperoxide and ethylbenzene hydroperoxide and catalysts such asmolybdenum, tungsten, titanium dissolved moieties are utilized. Theprocess also employs the use of base such as sodium hydroxide and thelike. A refinement of the above method is claimed in British Pat. No.1,198,327 wherein a technique for the recovery and recycle of thehydroperoxide successor materials, typically alkylaromatics, isdescribed.

Other prior art processes relating to liquid phase oxidation processesfor olefin oxidations include various specific oxidation catalysts asfound in US. Pat. Nos.

2,741,623, 2,837,424, 2,974,161 and 2,985,668; another patent teachesthe use of water immiscible hydrocarbon solvents alone or in thepresence of polymerization inhibitors such as nitrobenzene (U.S. Pat.No. 2,780,635) or saturated hydrocarbons (U.S. Pat. No. 2,780,634);another method describes the use of neutralizers such as alkali metaland alkaline earth metal hydroxides or salts of these metals (U.S. Pat.No. 2,838,524); another route involves the use of certain catalysts inthe alkaline phase (U.S. Pat. No. 2,366,724). Each of the foregoingrepresent various prior art approaches to overcoming the problemsencountered in the utilization of a liquid phase oxidation process toobtain olefin oxides. Additionally, in most of the prior art casesdiscussed above, selectivities to the epoxide are below 50 percent, andbecome even lower when used with alpha-olefins which are well known tothe art as being more difficult to epoxidize.

It is also known that olefins can be oxidized to olefin oxides, in theliquid phase, with molecular oxygen, in the presence of heavy metalcatalysts such as salts of cobalt, vanadium, manganese and copper.

SUMMARYOF THE INVENTION In accordance with the present invention, it hasbeen unexpectedly found that transition metal complexes of fluorinated1,3-diketones and hindered carboxylic acids, catalyze the reaction ofolefins in the liquid phase with molecular oxygen to produce epoxides inselectivities of up to 69 percent. The efficiency of these transitionmetal fluorinated diketone-hindered carboxylic acid complexes isbelieved due to the fact that if transition metals such as cobalt are toact effectively as oxidation catalysts, said metals must have an optimumoxidation potential. Ligand groups attached to the transition metal,i.e., cobalt, act as modifiers of the oxidation potential of the metal.Fluorinating the alkyl groups of the ligands increases theelectronegativity of the ligands and decreases the strength of thetransition metal peroxide bonding, i.e., the bonding between MO and asthis bonding becomes weaker, the rate of oxidation increases. However,if the M-O bond becomes too weak, the catalyst complex is unstable,hence the need for optimizing this bond strength. It has also beenunexpectedly found that when the transition metal complexes containneoacids or hindered acids as ligands, more generally described as saltsof alpha trisubstituted carboxylic acids that the oxidation potential ofthe transition metal is modified suitably to result in increased ratesof reaction and selectivities to the epoxide products when said modifiedtransition metal complexes are employed as catalysts in a liquid phase,direct oxidation of olefins process.

The transition metal complexes utilized in the present inventioncontaining the kinds of ligands hereinal' ter described, are found to bemore selective for the formation of epoxides and in addition, they donot react with lower carboxylic acids such as formic acid and the like.Hence, the oxidation activity of these catalysts at higher olefinconversions, decreases much slower than the prior art recognized cobaltoxidation catalysts, such as cobalt oxide and cobalt carbonate, cobaltacetylacetonate and cobalt carboxylates.

The catalysts which may be employed in the present invention may begenerally described as transition metal complexes of fluorinateddiketones and containing hindered acid ligands. More particularly, thesetransition metal complexes may be represented by the following genericformula:

wherein M is a transition metal, R is an anion of an 10 including alphatrisubstituted carboxylic acid having the following formula:

from C to C carbon atoms, n of the generic formula above is a numberfrom 1 to 2, preferably however, n is 1.2 to 1.5. M of the above formulamay in general be a transition metal, preferably, however, M is cobaltor manganese; most preferably cobalt is the metal employed.

Suitable ligand precursors useful in making suitable l5hexafluoro-3(pentafluoroethyl)-2,4-pentanedione.

The above catalyst species are prepafed in situ in the reaction chamber,prior to, or during the course of the reaction by adding sufficientamounts of the cobalt salt of a hindered carboxylic acid such as cobaltwh rein R, R", r yl gr p n i ng fr m 20 neodecanoate together withsufficient amount of fluorito 20 carbon atoms, preferably from 1 to 10and most preferably from 1 to 6 carbon atoms; R, and R of the abovegeneric formula are fluorinated aliphatic or aromatic hydrocarbon groupscontaining from C to C nated 1,3-diketone, such as decafluoro2,4-heptadione along with sufficient solvent and molecular oxygen.During the course of this reaction, a catalyst species represented bythe formula is believed to exist which carbon atoms, preferably from C,to C carbon atoms, provides the catalytic active species for the olefmoximost preferably from C to C carbon atoms; R of the above genericformula is a radical selected from the group consisting of hydrogenradicals, unsubstituted alkyl group radicals, and fluorinated aliphaticor arodation.

While not tending to be bound by any particular theory, it is believedthat the following is a plausible reaction mechanism when neoacid isused as a coligand and matic hydrocarbon groups of C to C carbon atoms,when neoacid anhydride is present.

preferably C to C carbon atoms, most preferably 1 Neoacid ColigandH-OCOR HOGOR III In Presence of Neoacid Anhydride Side Reactions RCOOR"-CH CH=CH +RCOOH+ ith. wonorr=om 02 R"CHCH=CH R"-GHG CHi By way ofbackground 1,3-diketones are a class of organic compounds believed toexist during reactions in a keto-enol tautomeric equilibrium, saidequilibrium may be represented by the general structures:

wherein R and R may be alkyl, tTub r i rEiteda lkyl, aromatic,heterocyclic and other groups. The negative ion formed by the removal ofa proton from the above keto-enol structures may serve as a coordinatingligand to almost any positive ion of an element and form what is knownas a complex. The organometallic compounds as derived from thecoordination of the ligand ions and the metal ions are known as metalbeta diketones or metal beta keto-enolates. Under suitable conditionscationic, neutral and anionic metal complexes can be formed. Many of theneutral metal complexes are readily soluble in organic solvents and canbe vaporized and some distilled. The unusual properties of metal betadiketones have been studied for many years. The ligand ions of betadiketones may form complexes with metal ions in many ways; they may formmonomeric complexes, they may form polymeric complexes, they may formmixed ligand complexes or they may form various types of isomericcomplexes.

During the operation of the present invention, it is believed, however,that the active catalyst species does not contain 2,-bidentate diketoneligands per gramatom of cobalt since it has been demonstrated that boththe rate and selectivity to epoxide is increased when the ratio ofcobalt to bidentate diketone ligands was changed from 1% to 1/15 or1/l.3.

in another preferred embodiment, the process may be carried out in thepresence of an additional amount of carboxylic acid anhydride. it hasbeen unexpectedly discovered that when an amount of the anhydride of thecarboxylic acid ligand is present in the reaction mixture, the rate ofepoxidation is increased as well as the selectivity. It has been foundthat, e.g., the rate of olefin conversion is increased, as theneodecanoic anhydride concentration increases up to a ratio of anhydrideto cobalt of about :1. The anhydride may be added in the beginning ofthe reaction or in stages of the reaction but it is preferred tocontinuously add anhydride throughout the reaction in order to maintaina more or less constant concentration. Stable anhydrides whic l'i arestable under the conditions of the epoxidation such as cisl,2-cyclohexane dicarboxylic acid anhydride do not have any effect onthe reaction. Suitable anhydrides that will enhance the reaction ratesand selectivities include a, a-dimethyloctanoic acid anhydride, amethyla ethyloctanoic acid anhydride, 0: methyl, or ethylheptanoic acidanhydride, neodecanoic acid anhydride and the like.

Olefins which may be employed in the present invention include those ofthe ethylenic and cycloethylenic series having from 2 up to 20 carbonatoms per molecule, for example, ethylene, propylene, butenes, pentenes,hexene, heptene, octene, nonene, dodecene, pentadecene, heptadecene,octadecene, cyclobutene, cyclopentene, cyclohexene, cyclooctene, etc. Ofparticular interest, utility and convenience are the olefins containingfrom 2 to 12 carbon atoms, including the alkyl substituted olefins, suchas 2-methyl l-butene, 2- methyl 2-butene, 2-methyl propene, 4-methyl 2-pentene, 2-ethyl 3-methyl l-butene, 2,3-dimethyl 2- butene and 2-methylZ-pentene. The process, however, is also useful with acyclic, aliphatic,terminal monoolefins where the carbon atoms of the carbon-carbon doublebond have three hydrogen substituents, particularly the normal acyclic,a-olefins, such as propylene, lbutene, l-pentene, l-hexene, l-heptene,l-octene, ldodecene; also preferred are the substituted olefins havingalkyl substitution at the beta carbon atoms, such as 2-methylheptene-1,Z-methyloctene-l ,2- ethylheptene-l,Z-methylcyclohexane, 2 methyl-2-ethylhexened and the like. Other suitable olefinic compounds includebutadienes, isoprene, pentadienes, hexadienes and the like. Thecatalysts are also useful in the epoxidation of olefins, which aresubstituted as well as unsubstituted. By substituted is meant olefinchains having groups such as esters and others attached thereto. Thecatalysts are'also useful for the epoxidation of polymers havingterminal double bonds, such as butadiene polymers, isoprene polymers,butadienestyrene copolymers and the like. Particularly, suitable olefinfeedstocks contemplated include the pure olefin or mixtures thereof orolefin stocks containing as much as 50 percent of saturated compounds.Olefin feed materials include those formed by cracking petroleum stocksuch as hydrocarbon oils, paraffin wax, lubricating oil stocks, gasoils, kerosenes, naphthas and the like. I

The reaction temperature used in liquid phase olefin oxidations by thepresent invention are not critical and they may range from a lower limitbelow which oxidation either proceeds too slowly or follows a courseother than that leading to olefin oxides to an upper limit for thetemperature being a threshold above which substantial decomposition,polymerization, or excessive oxidative side reactions occur therebyleading to undesirable side reactions and products which substantiallydetract from the yield of the olefin oxide. in general, however,temperatures will be in the range of from to 150C, more preferably to C.

Subatmospheric, atmospheric or superatmospheric pressures are suitablefor use in the instant invention, that is, pressures ranging from 0.5 to150 atmospheres may be employed, preferably, however, pressures will bein the range of from 1 to atmospheres. The pressures selected will ofcourse depend upon the characteristics of the individual olefin, whichis to be oxidized and which would be suitable in combination with thetemperatures of the reaction.

The process of the invention is preferably conducted, in the liquidphase, in solvents or diluents which are substantially oxidativelyinert, thermally stable and liquid at the reaction temperature andpressure. Materials, suitably employed as solvents includehalomonoaromatics, such as chlorobenzene, bromobenzene anddichlorobenzene, saturated aliphatic, alicyclic, or aromatic nitrileshaving from 2 to 18 carbon atoms, preferably from 2 to 18 carbon atoms,suitable alicyclic and aromatic nitriles having up to 6 carbon atoms inthe ring and including cycloalkane nitriles and the like. Also suitableas solvents are alcohols, both aliphatic and aromatic having from 2 to18 carbon atoms and from 1 to 2 hydroxy groups; preferably however,chlorinated aromatics are the best all round solvents.

The source of oxygen is not critical and oxygen may be suitably chargedas pure molecular oxygen or diluted with an inert gas such as nitrogenor argon. Air is a suitable oxygen-containing gas. Particularlypreferred, however, for use in the present invention is molecular oxygenwithout additional inert gas diluents.

The transition metal complex catalysts are preferably present incatalytic amounts relative to the olefinic reactant. Amounts of catalystare generally in the range of from 0.1 to 0.001 molar, preferably from0.05 to 0.008 and most preferably, from 0.01 to 0.015 molar. The amountof olefin employed is generally in the range of from 0.01 to 4 molar,preferably from 0.1 to 2 molar and most preferably from 0.1 to 1.0molar. The amount of cobalt salt of a-trisubstituted carboxylic acidssuch as cobalt neodecanoate employed is from 0.005 to 0.02 preferably0.01 molar. The amounts of acid or acid anhydride coligand such asneodecanoic acid and the like are in the range of from 0.005 to 0.5,preferably 0.1 to 0.5, most preferably about 0.2 molar. The transitionmetal complex is produced in situ during the course of the reaction bythe addition of the proper amounts of the metal salt of the alphatrisubstituted carboxylic acid, i.e., cobalt neodecanoate to which isadded certain amounts of a 1,3-diketone and additionally an amount ofthe anhydride of the neodecanoic acid employed may also be used toenhance the rate of the reaction.

The presence for example of a small amount from 10 to 20 'moles per gramatom of metal of free hindered acid or its anhydride will help toenhance the rate of reaction and selectivity to the epoxide.

In a typical reaction procedure, chlorobenzene, octene-l, cobaltneodecanoate, l,l,1,5,5,5-hexafluoro 2,4-pentadione and neodecanoic acidare charged to an all glass reactor equipped with a mechanical stirrer,a condenser and a gas inlet. The reaction mixture is heated underconstant stirring to 100C., while oxygen is passed through. Samples arewithdrawn and analyzed by gas chromatography against known referencestandards.

The olefin oxide products of the present invention are materials ofestablished utility and many are chemicals of commerce. For example,illustrative olefin oxides which are readily prepared by the process ofthe present invention such as propylene oxide, 1,2- epoxybutane,1,2-epoxydodecene, 1,2-epoxyheptadecane are formulated into usefulpolymers by polymerization or copolymerization as disclosed by U.S. Pat.Nos. 2,815,343, 2,871,219 and 2,987,489.

To further illustrate the improved process of the present invention, thefollowing examples are provided, however, it is to be understood thatthe details thereof, are not to be regarded as limitations as they maybe varied as will be understood by one skilled in the art.

EXAMPLE 1 In an all glass reactor equipped with a mechanical stirrer, acondenser and a gas inlet were introduced 60 ml. chlorobenzene, 15 g. ofoctene-l, 0.257 g. (0.00063 mole) cobalt neodecanoate, 0.170 g. (0.00082mole) 1,1,l,5,5,5-hexafluoro-2,4-

pentanedione and 1.5 g. neodecanoic acid. The reaction mixture washeated under constant stirring at C. while oxygen was passed through.Periodically samples were withdrawn and analyzed by gas chromatography.The results are set forth in Table 1 below.

EXAMPLE 2 A similar experiment as in Example (1) was performed with 0.63m moles of cobalt neodecanoate, 0.95 m moles of1,1,1,5,5,5-hexafluoro-2,4- pentanedione and 3.0 g of neodecanoicanhydride instead of neodecanoic acid. The experimental results arelisted in Table 1 below.

EXAMPLE 3 In this experiment, the catalyst complex was prepared from0.340 g (0.84 m mole) cobalt neodecanoate and 0.309 g (1.0 m mole)l,1,1,5,5,6,6,7,7,7- decafluoro-2,4-heptanedione which were mixed with asolution of 15 g octene-l and 3.0 g neodecanoic anhydride in 60 ml ofchlorobenzene. The reaction conditions were the same with those ofExamples (1) and' (2). After the octene-l conversion was about 10percent additional neodecanoic anhydride was introduced at the rate of1.7 ml per hour. The results of this Example may be found in Table 1below.

EXAMPLE 4 In order to demonstrate the advantage of using the cobaltcomplexes of the present invention, an experiment similar to Example (1)was conducted where the catalyst was 0.340 (0.84 m mole) of cobaltneodecanoate. The result of this run is summarized in Table 1 below.

TABLE 1 EXAMPLE In a glass reactor equipped with a mechanical stirrer, acondenser and a gas inlet were introduced 60 ml. chlorobenzene, g ofoctene-l, 0.401 g of manganese naphthenate (0.44 mole) and 0.186 g (0.88mole) 1,1,- l,5,5,5-hexafluoro-2,4-pentanedione. The reaction mixturewas heated with continuous stirring while oxygen was bubbled through.Chromatographic analysis of the reaction mixture at one-half hour timeintervals in- TABLE III A similar set of experiments was performed byusing manganese as the metal of the metal-ligand complex and again theselectivity increased with the diketonate ligands of higherelectronegativity.

EXAMPLES 1520 To demonstrate a further improvement in selectivity byusing as a coligand a hindered carboxylic acid (neoacid) which has ahigher pKa than straight chain aliphatic acids, a series of experimentswas carried out where the catalyst was made in situ from the cobalt saltof a number of carboxylic acids of different pKas. 0.6 m moles of thecobalt salt was added to a mixture of 60 ml. chlorobenzene and 15 goctene-l. To the total mixture 0.250 g (1.2 m moles) ofl,l,l,5,5,5-hexafluor0- 2.4-pentanedione was added and the mixture washeated at 100C. while oxygen was passed through. The results of theseruns are tabulated in the following Table 111 and show that higher ratesand selectivities are obtained with weaker carboxylic acid coligands.

Selectivity and rate vs acidity of ligand (L) Acid CFaCOOH CHsCOOHCTCOOH Neodecanoic pKa 0.10 2.98 4.75... 4.851. 5.05. Percentselectivity (max) 23 27 30 55.

Relative rate V. slow dicated that maximum selectivity to epoxide was 22percent at 48.5 percent conversion. This example illustrates thatmanganese salts are useful catalysts.

EXAMPLES 6-14 A series of experiments were performed where the type ofligands used were of different degrees of electro-negativity. Forinstance, cobalt complexes were synthesized, in situ or separately, withdimethylglyoxime, acetylacetone, cis-l ,2-cyclobutanedinitrile, 1,1-,l-trifluoro-2,4-pentanedione and 1,1,l,5,5,5-hexafluoro-Z,4-pentanedione by using 2 moles of ligand per atom ofcobalt. These catalyst complexes were used in separate expoxidationexperiments at 0.008 molar concentration. The solvent was chlorobenzeneand the temperature 100C. Mechanical stirring was applied throughouttheruns and oxygen was passed EXAMPLES 21-23 These Examples (21-23) showthe effect of the ligand/cobalt ratio on selectivity. Three experimentswere conducted with 15 g octene-l in ml. chloro" benzene with a ratio offluorinated. diketone/cobalt of 2, 1.3 and 1.5. Cobalt neodecanoate0.170 g (0.42 m moles) was used in each case with 0.175, 0.114 and 0.131g of 1,1 ,1,5,5,5-hexafluoro-2,4-pentanedione respectively. 3.0 g ofneodecanoic anhydride was added to each reaction mixture and oxygen waspassed through with stirring at a reaction temperature of C. Theselectivities obtained in these runs are tabulated in the followingTable IV. The results obtained indicate that the active catalyst speciesdoes not contain two bidentate ligands per molecule of cobalt but ratherthe catalyst complex which exists contains from about 1.3 1.5 bidentateligands per molecule of cobalt.

through the solution. The progress of the epoxidation TABLE IV wasfollowed by periodically analyzing samples with gas Olefin phasechromatography. The results of these runs are 55 HF'Ac/com select'v'ty(Mam Conversm" shown in the following Table ll and they indicate that22'? 3:3 by using ligands with higher electronegativity, the se- 1.569.7 6.5 lectivity towards the formation of epoxide is increased. 111,5v5McxunuomaMcnmmdhmc TABLE 1r Ligand electronegativity- -ON C-C=NOHMetal salt C-CINOH RCOO-AcAc CN TF-Ac 1 HF-Ac 9 Remarks Co actuate 0 1629 31 40 Percent selectivity of epoxide. Mn naphthenate 1 2 19. 5 22 Do.

I '1 F-Ae =1,1,1-1rilluoroQA-pentanedione. 1 HF-Ac=1,1,1,5,5,5-hexafiuoro-2,4-pentanedione.

EXAMPLE 24 Chlorobenzene 60 ml., 14.9 g Z-methylheptene-l. 0.425 g (1.05m moles) cobalt neodecanoate, 0.387 g (1.25 m mole)1,1,1,5,5.6,6,7,7,7-decafluoro-2,4- heptanedione and 3.0 g neodecanoicanhydride were placed in the same glass reactor as in the previousexperiments (Examples 5-23) and were heated at 100C. with constantstirring while oxygen was bubbled through the reaction mixture. Sampleswere periodically withdrawn and analyzed by Gas Phase Chromatographyindicating a fast reaction rate (40 percent olefin conversion in onehour) and a maximum selectivity to the epoxide of 72.7 percent. ThisExample demonstrates the significant selectivities obtained with 2-substituted olefins as feedstocks.

EXAMPLE 25 In a glass reactor equipped with a mechanical stirrer, acondenser, a bubbler and a thermometer were introduced 55 ml ofchlorobenzene, 20 g (0.178 mole) octene- 1 0.340 g (0.84 m mole) ofcobalt neodecanoate, 0.310 g (1.0 m mole)1,1,1,5,5,6,6,7,7,7-decafluoro- 2,4-heptanedione and 3.0 g neodecanoicanhydride. The reaction mixture was heated at 100C under constantstirring while oxygen was passed through. Maximum selectivity was 56percent at 4.6 percent olefin conversion.

EXAMPLE 26 This experiment was conducted in a similar manner as Example25 but with 60 ml chlorobenzene, g (0.133 mole) octene-l, 0.510 g (1.25m mole) cobalt neodecanoate, 0.464 g (1.5 m mole) 1,1 ,1 ,5,5,6,6,7,7,-7-decafluoro-2,4-heptanedione and 3.0 g neodecanoic anhydride. Maximumselectivity to epoxide was 60.1 percent at 6.0 percent conversion.

What is claimed is:

1. A process for preparing an olefin oxide by contacting a monoolefincontaining from 3 to carbon atoms in the liquid phase at a temperatureof from 70 to 150C, with molecular oxygen in the presence of a catalyticamount of a transition metal complex of fluorinated diketone, saiddiketone complex being produced in situ by contacting cobaltneodecanoate with a fluorinated 1,3-diketone in at least a 1:2 moleratio of cobalt neodecanoate to 1,3-diketone, said diketone complexhaving the following generic formula:

Ra J11 wherein M is cobalt, R is an anion of neodecanoic acid; R and Rare radicals independently selected from the group consisting offluorinated aliphatic hydrocarbon chains of from 1 to 20 carbon atoms; Ris a radical selected from the group consisting of hydrogen,unsubstituted alkyl groups having from 1 to 20 carbon atoms andfluorinated aliphatic hydrocarbon chains of 1 to 20 carbon atoms; n is anumber from 1 to less than or equal to 2, said contacting beingconducted in the presence of a solvent and thereafter recovering a yieldof said olefin oxide. 7 2. The process of claim 1 wherein R and R are C,to C fluorinated aliphatic hydrocarbon chains.

3. The process of claim 2 wherein R is hydrogen.

4. The process of claim 3 wherein n is 1.5.

5. The process of claim 4 wherein the monoolefin is selected from thegroup consisting of 2-methylheptenel, propylene, butene- 1, octene-l andmixtures thereof.

6. The process of claim 5 wherein the cobalt transition complex is thecobalt neodecanoate complex of 1,1,] ,5,5,-5-hexafluoro 2,4-pentadione.

7. The process of claim 5 wherein the cobalt transition complex is thecobalt neodecanoate complex of1,1,l,5,5,-6,6,7,7,7-decafluoro-2,4-heptanedione.

8. The process of claim 7 wherein the monoolefin is 2-methylheptene- 1.

9. The process of claim 1 wherein said monoolefin contacting isconducted in the presence of neodecanoic anhydride.

10. The process of claim 9 wherein the amount of neodecanoic anhydridepresent is in the range of from 1:1 to about 20:1 moles per mole ofcobalt present in the reaction zone.

11. The process of claim 1 wherein said diketone complex is present incatalytic amounts of from 0.1 to 0.001 molar.

1. A PROCESS FOR PREPARING AN OLEFIN OXIDE BY CONTACTING A MONOOLEFINCONTANING FROM 3 TO 20 CARBON ATOMS IN THE LIQUID PHASE AT A TEMPERATUREOF FROM 70* TO 150*C., WITH MOLECULAR OXYGEN IN THE PRESENCE OF ACATALYTIC AMOUNT OF A TRANSITION METAL COMPLEX OF FLUORINATED DIKETONE,SAID DIKETONE COMPLEX BEING PRODUCED IN SITU BY CONTACTING COBALTNEODECANOATE WITH A FLUORINATED 1,3-DIKETONE IN AT LEAST A 1:2 MOLERATIO OF COBALT NEODECANOATE TO 1,3-DIKETONE, SAID DIKETONE COMPLEXHAVING THE FOLLOWING GENERIC FORMULA:
 2. The process of claim 1 whereinR1 and R3 are C1 to C10 fluorinated aliphatic hydrocarbon chains.
 3. Theprocess of claim 2 wherein R2 is hydrogen.
 4. The process of claim 3wherein n is 1.5.
 5. The process of claim 4 wherein the monoolefin isselected from the group consisting of 2-methylheptene-1, propylene,butene-1, octene-1 and mixtures thereof.
 6. The process of claim 5wherein the cobalt transition complex is the cobalt neodecanoate complexof 1,1,1,5,5,-5-hexafluoro 2, 4-pentadione.
 7. The process of claim 5wherein the cobalt transition complex is the cobalt neodecanoate complexof 1,1,1,5,5,-6,6,7,7,7-decafluoro-2,4-heptanedione.
 8. The process ofclaim 7 wherein the monoolefin is 2-methylheptene-1.
 9. The process ofclaim 1 wherein said monoolefin contacting is conducted in the presenceof neodecanoic anhydride.
 10. The process of claim 9 wherein the amountof neodecanoic anhydride present is iN the range of from 1:1 to about20:1 moles per mole of cobalt present in the reaction zone.
 11. Theprocess of claim 1 wherein said diketone complex is present in catalyticamounts of from 0.1 to 0.001 molar.